Thousands of pet dogs are part of a citizen science project to understand memory and cognition in old age - maybe old dogs can teach us some new tricks.
Dr Matt Kaeberlein leads the Dog Aging Project and says his longevity research on dogs may unlock some key mysteries about the biology of aging and what we can do about it.
The project started 8 years ago, collecting data over the course of a dog's life and so far 40,000 dogs have taken part, making it the largest longitudinal study of aging in animals.
Dr Matt Kaeberlein with dogs Chloe and Dobby. Dr Kaeberlein is a founder of the Dog Aging Project at the University of Washington. Photo: The Dog Aging Project
About ten years ago, it occurred to Kaeberlein that the science he had been working on since graduate school might actually be useful to help his own dogs live longer.
Kaeberlein has a 12-year-old German Shepherd, Dobby – named after the Harry Potter character because of the big ears he had as a puppy.
“He’s an awesome dog, I love Dobby, he’s one of those special dogs – although of course everybody says that - I would say he’s the best dog in the world.”
Dogs age biologically more rapidly than humans but Kaeberlein says it’s a little bit more complicated than the old saying that one human year equals seven dog years.
“Both because different sizes of dogs actually age at different rates, so big dogs age faster than small dogs, and because it’s not exactly what we’d call a linear relationship.”
When dogs are young, Kaeberlein says, they age more like 10 years for every human year. As they get older it slows down and it becomes more like three years to one human year.
As they age, dogs can get almost all the same spectrum of diseases that humans do, he says. “Importantly, they are age-associated in dogs.”
Because dogs age a lot like us but age more rapidly, it means understanding the biological aging process in dogs can be studied in a reasonable time frame, he says.
“The last 20 years have been really remarkable in the field of aging biology, learning what that means at the cellular level. We know a lot about the types of changes, and most people would call it damage, that accumulates with age at the cellular level.”
There are nine hallmarks of aging representing most of what we know about the conserved mollecular processes that happen in aging, he says.
“That includes things that people may have heard about before like telomere shortening, cellular senescence or mitochondrial damage.”
We don’t know everything about the biological aging process, but Kaeberlein says scientists know enough to start to do something about it.
That’s what he’s most excited about.
The largest part of the dog aging study is observational and covers dogs, of all ages and sizes, that live in the United States.
Owners fill out a survey about their dog's home environment, diet, prior diagnosis of disease and provide a vet medical record.
Ten thousand of those dogs will have their genomes sequenced. One thousand dogs have annual large scale data sets recorded.
Kaeberlein has been excited by the first set of data that’s come in. That data is from a single time point, before the longitudinal phase kicked in.
“We’ve learned a lot of interesting stuff.”
“[These include] the impact of inbreeding on different diseases like cancer, the relationship between how frequently a dog is fed and its risk of developing future diseases, relationships between its sex and disease risk.”
“It’s been exciting, and I’d say we’re really at the tip of the iceberg in terms of diving in and analysing the data.”
Another part of the project is a clinical trial testing rapamycin, a drug used in humans to treat cancer and to prevent organ rejection in transplant patients.
“It was first approved to prevent organ transplant rejection, by the FDA, it’s also used clinically for a variety of other indications, some rare form of cancer. Sort of in parallel to that clinical use, about...14 years ago there was study published in mice that showed that treatment with rapamycin, starting in middle age could significantly increase lifespan.”
Since that study, Kaeberlein’s lab and others have shown not only had life span increased, “even from transient treatments in middle age in mice, you can either delay or in some cases actually reverse the functional declines that go along with aging”.
Kaeberlein argues that biologically age is the greatest risk factor for nearly every major cause of death and disability in developed countries.
“So, if we can understand that biology of aging, we really have an opportunity to have a much greater impact on healthy longevity – which is what we’re all after, not only in dogs but also in people.”
As a 51-year-old, Kaeberlein says over the years, studying aging has become more personal for him.
“Still at this point, most of what we know works to target the biology of aging are the obvious things like exercise and nutrition and trying to live a healthy lifestyle. I’m hoping that in the near future we’ll actually be able to do better than that.
“And in addition to those lifestyle factors, [we] some real promising interventions that can have a significant impact – probably first in dogs but I don’t think it’s too far after that that we’d be able to make some recommendations for people as well.”
